diff options
| author | Dominik Brodowski <linux@dominikbrodowski.net> | 2018-03-07 00:18:08 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2018-03-07 09:57:31 +0300 |
| commit | af52201d991624d2d5adce2c123805b3d42a8d4d (patch) | |
| tree | 6fcb0ec95c5ad0c7fff5dd51abb8df12c623dc53 /arch/x86/include | |
| parent | 4ddb45db30851b2269101ee8969f079b028dd257 (diff) | |
| download | linux-af52201d991624d2d5adce2c123805b3d42a8d4d.tar.xz | |
x86/entry: Do not special-case clone(2) in compat entry
With the CPU renaming registers on its own, and all the overhead of the
syscall entry/exit, it is doubtful whether the compiled output of
mov %r8, %rax
mov %rcx, %r8
mov %rax, %rcx
jmpq sys_clone
is measurably slower than the hand-crafted version of
xchg %r8, %rcx
So get rid of this special case.
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: luto@amacapital.net
Cc: viro@zeniv.linux.org.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/include')
| -rw-r--r-- | arch/x86/include/asm/sys_ia32.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/x86/include/asm/sys_ia32.h b/arch/x86/include/asm/sys_ia32.h index 32831905d97a..906794aa034e 100644 --- a/arch/x86/include/asm/sys_ia32.h +++ b/arch/x86/include/asm/sys_ia32.h @@ -55,6 +55,8 @@ asmlinkage long compat_sys_x86_fadvise64(int, unsigned int, unsigned int, size_t, int); asmlinkage long compat_sys_x86_fallocate(int, int, unsigned int, unsigned int, unsigned int, unsigned int); +asmlinkage long compat_sys_x86_clone(unsigned long, unsigned long, int __user *, + unsigned long, int __user *); /* ia32/ia32_signal.c */ asmlinkage long sys32_sigreturn(void); |